Bearing assembly for a support roller

ABSTRACT

A bearing assembly comprises at least one bearing for rotatably supporting a support roller having at least one hollow cylindrical portion. A support element is disposed directly or indirectly between a ring of the at least one bearing and the support roller. The support element comprises first and second hollow-cylindrical segments extending in the axial direction of the support roller. The first and second hollow-cylindrical segments are connected by a ring-shaped segment extending either in the radial direction of the support roller or at an angle to the radial direction.

The invention relates to a bearing assembly for a support roller, whichis formed in a hollow cylindrical manner at least in one segmentthereof, having a bearing that bears the support roller, wherein asupport element is disposed directly or indirectly between a ring of thebearing and the support roller.

Diverse possibilities are known in the prior art for the bearing ofsupport rollers. DE 1 738 837 U discloses a bearing assembly of theabove-mentioned type. Such a solution is also known from GB 592 043 A.DE 28 01 879 A1 shows another similar bearing assembly, wherein anelastomeric intermediate layer is also utilized for the purpose ofdampening the system. An axial end portion of a sleeve, which serves asa support element, radially enlarges and its radially outer portion iswelded to the cylindrical inner surface of the support roller. Otherbearing assemblies for the dampened bearing of a support roller areknown from AT 215 887, DE 24 00 701 A1 and U.S. Pat. No. 3,362,760.

It is common in all of the solutions that a relatively highmanufacturing expense must be incurred in order to produce the bearingassembly. In part, the manufacturing tolerances must be maintained asprecise as possible in order to obtain a bearing assembly having ahighly true running precision. Further, the rigidity of the design isalso sometimes not sufficient, in particular when—as in DE 28 01 879A1—radially-enlarged sleeve segments must be fixedly welded to theinterior of the support roller.

It is disadvantageous that the support roller assemblies have arelatively high weight. As a result, the loads that must be borne by thebearing assembly are high. Further, it is disadvantageous that largeloads can be transmitted into the bearing in case the axis of thebearing and the axis of the support bearing are improperlypositioned—for example in case corresponding loads act on the supportroller.

The object underlying the invention is to further develop a bearingassembly of the above-mentioned type so that it is possible to designthe assembly in a substantially lighter manner without having to acceptlarge stability losses. Further, a problem-free bearing of the sameshould be ensured by the bearing even if there are slight improperpositionings between the bearing and the support roller. In addition,this bearing assembly should be producible in a cost-effective manner.The tolerances required for the manufacturing should be allowed to be aslarge as possible without running into the danger of producing defectiveparts.

The solution of this object is characterized in that the support elementincludes two hollow-cylindrical segments extending in the axialdirection of the support roller and/or the bearing, whichhollow-cylindrical segments are connected by a ring-shaped segment thatextends in the radial direction or at an angle (between 0° and 45°) tothe radial direction.

Preferably, the hollow-cylindrical segments and the ring-shaped segmentare designed as a one-piece component.

The extension of the ring-shaped segment in the axial direction ispreferably at most 20%, particularly preferably at most 15%, of theextension of the hollow-cylindrical segment in the axial direction.

The ring-shaped segment can be disposed in the middle of the axialextension of the hollow-cylindrical segment.

The support element can be comprised of plastic, in particularpolyamide; the manufacture of the support element from a light metal, inparticular aluminum or magnesium, is also possible.

A radial circumferential surface of at least one hollow-cylindricalsegment spaced from the ring-shaped segment can be formed conicallystarting from the axial position of the ring-shaped segment. In thiscase, an improved axial retention of the support element on thesurrounding components is achieved. Preferably, it can be provided thatthe radius of the inner circumferential surface of the inner ring-shapedsegment of the support element decreases in the direction away from theaxial position of the ring-shaped segment.

In order to achieve a sufficient stability in spite of the achievedlight construction, it has proven itself to be advantageous when bridgesformed in a planar manner extending in the radial direction are providedbetween the ring-shaped segments. These bridges are preferably connectedwith the ring-shaped segment, wherein a particularly preferredembodiment provides a one-pieced embodiment of the ring-shaped segmentand the bridges. The bridges can axially extend between the ring-shapedsegment and the axial end portions of the support element. A furtherdevelopment provides that a plurality of bridges are disposedequal-distantly around the circumference of the hollow-cylindricalsegments, for example 4, 8 or 8 bridges, and further on both sides ofthe ring-shaped segment.

An intermediate ring can be disposed between the radially-inward-lyinghollow-cylindrical segment of the support element and the ring of thebearing. This intermediate ring can have at least one rim axiallysurrounding the ring of the bearing. The intermediate ring can be madeof metal, in particular steel or light metal.

Further, a dampening element made of elastomeric- or rubber material canbe disposed between the radial-outward-lying hollow cylindrical segmentof the support element and the support roller and/or between theradially-inward-lying hollow-cylindrical segment of the support elementand the intermediate ring or the ring of the bearing.

The dampening layer is preferably made of an elastomer, in particularpolyurethane, or is made of a rubber material.

The dampening element can have a hollow-cylindrical shape.

A sleeve can be disposed between the support roller and the dampeningelement. The sleeve can surround the dampening element by means of aring segment that extends radially inwardly. Further, the sleeve canaxially surround the support roller by means of a ring segment thatextends radially outwardly. It can be made, e.g., from metal plate. Asealing element, in particular an O-ring, can be disposed between thesupport roller and the sleeve.

Between at least two of the components: ring of the bearing,intermediate ring, hollow-cylindrical segment of the support element,dampening element, sleeve and support roller, a friction-increasingmedium can be applied or a coating made of a friction-increasing mediumcan be applied to at least one of the components.

For example and preferably, zinc can be utilized as thefriction-increasing medium. Accordingly, a galvanized metal plate (forthe sleeve), for example, can be provided in order to achieve thefriction-increasing effect. The zinc layer also advantageously resultsin a corrosion protection in the joint. Further, a zinc layer can beapplied in a very cost-effective manner.

The friction-increasing medium can also include diamond or boronnitride; in particular, it can include diamond paste. However, thefriction-increasing medium can also include silicon carbide or corundum.

The diamond, boron nitride, silicon carbide or corundum preferablyexists as grains having a diameter range between 1 μm and 100 μm, inparticular having a diameter range between 10 μm and 80 μm.

It is also possible that the grain-shaped material (e.g., the diamonds,silicon carbide, corundum or boron nitride) is bonded to the mentionedcomponents with a bonding agent. Preferably, a metallic layer isutilized as the bonding agent, in particular a layer of nickel. This canbe applied by a galvanizing process.

In the alternative, the coating having the friction-increasing propertycan also be a molybdenum layer. Preferably, this can be applied by flamespraying.

The at least one bearing is preferably designed as a roller bearing.

The support roller can be formed as a pipe having a constant wallthickness that is respectively borne at both axial end portions by abearing.

With the proposed solution, it results in an advantageous manner that avery light and nevertheless stable embodiment of the support rollerassembly can be achieved.

It is also advantageous that, in case of slight improper positioningsbetween the bearing and the support roller, it can be easily compensatedby a support element formed in a double T-shape in cross-section.

The necessary components are formed very simply, which means that themanufacture of the bearing assembly can take place in a very economicalmanner.

The preferably-provided dampening layer made of elastomeric- or rubbermaterial provides the rotational balancing and vibration decoupling.Further, transient loads can be better absorbed by it.

A further important advantage of the proposed solution is that, when thefriction-increasing coating is utilized, the torque transmission can besubstantially improved. The highest torques can be transmitted withoutleading to a detachment of the connection of the components.Furthermore, a slipping-through of components is excluded as much aspossible. This becomes noticeable in an especially advantageous mannerwhen rotational deviations occur during operation of the support roller,which can not develop any negative effects due to the selected design ofthe bearing assembly.

In other words, when the above-mentioned torque must be transmitted, asmaller or lighter conception of the bearing assembly is possible.

This result is achievable even with a relatively short press-fit betweenthe associated components.

The proposed bearing assembly is preferably utilized in pit mining andin this case, it is an important component of a support roller device.Here, a high requirement for qualitatively high-valued and light bearingassemblies exists that distinguish themselves by a long service life anda comfortable operation.

Exemplary embodiments of the invention are illustrated in the drawings.

FIG. 1 shows the radial cross-section through a bearing assembly havinga support roller that is borne by a bearing,

FIG. 2 shows the radial cross-section through a support element of thebearing assembly according to an alternative embodiment and

FIG. 3 shows in perspective illustration the support element of thebearing assembly in another alternative embodiment.

In FIG. 1, a bearing assembly 1 can be seen that serves to bear asupport roller 2 of a conveying device. A shaft 13 is illustrated, onwhich a deep groove ball bearing 3 is fixed. The outer ring 4 of thedeep groove ball bearing 3 supports an intermediate ring 6 that has arim 7 on one side, which rim axially surrounds the outer ring 4 andforms an axial stop for it.

The support roller 2 is formed as a hollow-cylindrical component, i.e.as a pipe, wherein a bearing assembly 1 is disposed in both axial endportions, as can be seen in the Figure. A sleeve 9 is pressed into theinwardly-directed surface of the support roller 2 and sits in thesupport roller 2 with a press-fit. Between the sleeve 9 and theintermediate ring 6, a dampening element 8 made of elastomeric- orrubber material is disposed radially further outwardly and a supportelement 5 is disposed radially further inwardly.

In the present case, the dampening element 8 is designed as ahollow-cylindrical layer. The elastomeric- and/or rubber material can bedirectly connected with the sleeve 9 and/or with the support element 5by an injection molding process or by a vulcanization process.

It is important that the support element 5 includes twohollow-cylindrical segments 5′ and 5″ extending in the axial direction aof the support roller 2 and/or the bearing 3, which segments 5′ and 5″are connected by a ring-shaped segment 5′ extending in the radialdirection r. It is also possible that the ring-shaped segment 5′″ formsan angle (not illustrated) with the radial direction; this angle can beup to 45°.

Thus, the support element 5 has a double T-shaped design in theillustrated radial cross-section, which makes it possible that improperpositionings between the axes of the support roller 2 and the bearing 3can be elastically compensated by the elastic effect of the dampeningelement 8 without inducing large forces in the bearing.

This is achieved and/or fostered by making the extension t of thering-shaped segment 5′″ in the axial direction a at most 20%, preferablyat most 10% to 15%, of the extension T of the hollow-cylindricalsegments 5′, 5″ in the axial direction a.

It is advantageous that the sleeve 9 is disposed in at least one axialsegment portion of the support roller 2 between the inner cylindricalsurface of the support roller 2 and the dampening element 8; the sleeve9 axially overhangs on one side and has a ring segment 11 extendingradially outwardly at the axial end portion of the support roller 2.This ring segment 11 can also be called a flange and forms a definedaxial stop for the support roller 2. An axial fixing of the supportroller 2 relative to the sleeve 9 is thus possible in a simplifiedmanner.

The support roller 2 and the sleeve 9 are thus fixedly connected witheach other, which can be facilitated, e.g., by a weld. The sealingbetween the sleeve 9 and the support roller 2 can be produced by a sealelement 12—in the exemplary embodiment in the shape of an O-ring.

On the other side, a ring segment 10 surrounds the dampening element 8at the other axial end of the sleeve 9 and in this respect provides anaxial stop for the dampening element 8.

In FIG. 2, it can be seen that it can also be provided for the supportelement 5 that the radial inner surface of the hollow-cylindricalsegment 5″ (and/or the radial outer surface of the hollow-cylindricalsegment 5′ —is not illustrated) can have a conical shape. In the presentcase, the radial inner surface of the hollow-cylindrical segment 5″extends on both sides of the middle, i.e. on both sides of thering-shaped segment 5′″, towards the axial ends of thehollow-cylindrical segment 5″ in a radially conically sloping manner.The cone angle α is illustrated in an exaggerated manner here. In mostcases, it is in the range of a few degrees, e.g., 1 to 5°. As a resultof this, an improved axial retention exists between the support element5 and the intermediate ring 6.

In FIG. 3, it is illustrated, by which measure a substantialstabilization increase of the support element 5 can be achieved, withouthaving to accept the weight of a solid sleeve. Here, bridges 14 areprovided on both sides of the ring-shaped segment 5′″, the bridges 14are designed as one-piece with the segments 5′, 5″, 5′″ and the bridges14 axially extend from the ring-shaped segment 5′″ up to the axial endsof the segments 5′, 5″. In the exemplary embodiment, four bridges areprovided (on each side of the ring-shaped segment 5′″) that are disposedin an equal-distant distribution around the circumference.

REFERENCE NUMBER LIST

-   1 Bearing assembly-   2 Support roller-   3 Bearing (ball bearing)-   4 Ring of the bearing (outer ring)-   5 Support element-   5′ Hollow-cylindrical segment-   5″ Hollow-cylindrical segment-   5′″ Ring-shaped segment-   6 Intermediate ring-   7 Rim-   8 Dampening element-   9 Sleeve-   10 Ring segment-   11 Ring segment-   12 Seal element (O-ring)-   13 Shaft-   14 Bridge-   a Axial direction-   r Radial direction-   t Extension of the ring-shaped segment-   T Extension of the hollow-cylindrical segment-   A Angle

1.-30. (canceled)
 31. An apparatus for rotatably supporting a supportroller having at least one hollow cylindrical portion and extending inan axial direction, the apparatus comprising: at least one bearingconfigured to rotatably support the support roller, a support elementconfigured to be disposed directly or indirectly between a ring of theat least one bearing and the support roller, wherein the support elementcomprises first and second hollow-cylindrical segments extending in theaxial direction of the support roller, the first and secondhollow-cylindrical segments being connected by a ring-shaped segmentextending one of: (i) in a radial direction of the support roller and(ii) at an angle to the radial direction, and an intermediate ringdisposed between said ring and the first hollow-cylindrical segment,which is disposed radially inward of the second hollow-cylindricalsegment.
 32. The apparatus according to claim 31, wherein the first andsecond hollow-cylindrical segments are integrally formed with thering-shaped segment as a one-piece component.
 33. The apparatusaccording to claim 31, wherein the ring-shaped segment has a length inthe axial direction that is up to 20% of the length of the first andsecond hollow-cylindrical segments in the axial direction.
 34. Theapparatus according to claim 33, wherein the ring-shaped segment isdisposed in the middle of the length of the first and secondhollow-cylindrical segments in the axial direction.
 35. The apparatusaccording to claim 31, wherein the support element comprises polyamide.36. The apparatus according to claim 31, wherein the support element ismade of aluminum or magnesium.
 37. The apparatus according to claim 31,wherein at least one of the first and second hollow-cylindrical segmentshas a radially-inward circumferential surface that extends conically inthe axial direction away from the ring-shaped segment.
 38. The apparatusaccording to claim 37, wherein the radially-inward circumferentialsurface of the first hollow-cylindrical segment has a radius thatdecreases in the axial direction away from the ring-shaped segment. 39.The apparatus according to claim 31, further comprising at least oneplanar bridge extending at least substantially in the radial directionand connecting the first and second hollow-cylindrical segments.
 40. Theapparatus according to claim 39, wherein the at least one bridge isconnected with the ring-shaped segment.
 41. The apparatus according toclaim 40, wherein the at least one bridge axially extends between thering-shaped segment and each respective axial end portion of the supportelement.
 42. The apparatus according to claim 40, wherein a plurality ofbridges are disposed equal-distantly around the circumference of thefirst and second hollow-cylindrical segments.
 43. The apparatusaccording to claim 31, wherein the intermediate ring has at least onerim axially surrounding the ring of the bearing.
 44. The apparatusaccording to claim 43, wherein the intermediate ring is made of metal.45. The apparatus according to claim 31, further comprising a dampeningelement made of an elastomeric material or a rubber material disposed atleast one of: (i) between the second hollow-cylindrical segment and thesupport roller, and (ii) between the first hollow-cylindrical segmentand the intermediate ring or the ring of the bearing.
 46. The apparatusaccording to claim 45, wherein the dampening element has ahollow-cylindrical shape.
 47. The apparatus according to claim 46,further comprising a sleeve disposed between the support roller and thedampening element.
 48. The apparatus according to claim 47, wherein thesleeve includes a radially-inwardly extending flange that axiallysurrounds at least a portion of the dampening element in the radialdirection.
 49. The apparatus according to claim 48, wherein the sleeveincludes a radially-outwardly extending flange that axially surrounds atleast a portion of the support roller in the radial direction.
 50. Theapparatus according to claim 49, wherein the sleeve is made from metalplate.
 51. The apparatus according to claim 50, further comprising anO-ring disposed between the support roller and the sleeve.
 52. Theapparatus according to claim 31, wherein, between at least two of thefollowing components: the ring of the bearing, the intermediate ring,the first and second hollow-cylindrical segments, a dampening element, asleeve and the support roller, a friction-increasing agent is applied ora coating made of a friction-increasing agent is applied to at least oneof said components.
 53. The apparatus according to claim 52, wherein thefriction-increasing agent comprises zinc.
 54. The apparatus according toclaim 52, wherein the friction-increasing agent comprises at least oneof diamond and boron nitride (c-BN).
 55. The apparatus according toclaim 54, wherein the friction-increasing agent is diamond paste. 56.The apparatus according to claim 52, wherein the friction-increasingagent includes silicon carbide or corundum.
 57. The apparatus accordingto claim 52, wherein the friction-increasing agent includes grains of atleast one of diamond, boron nitride, silicon carbide and corundum, thegrains having a diameter between 10 μm and 80 μm.
 58. The apparatusaccording to claim 31, wherein the at least one bearing is a rollerbearing.
 59. The apparatus according to claim 31, wherein the supportroller is formed as a pipe having a constant wall thickness.